This invention relates to devices for cutting and stripping insulated wire, and in particular, to an improved cutterhead assembly for use with the same.
Typically, electrical harnesses are produced by cutting insulated wire to a desired length, stripping the insulation from the cut ends, and then applying terminals to one or both ends of the cut length. The wire is usually contained on a supply coil and fed in a desired increment of length to a cutting and stripping station by cooperating feed rolls or belts.
A conventional cutting and stripping station includes a pair of opposed cutterhead assemblies, each including a central cutting knife and a pair of stripping knives which are located in spaced relation on either side of the cutting knife. After a predetermined length of wire has been positioned between the upper and lower cutterhead assemblies, the knives on the upper and the lower cutterhead assemblies are moved toward each other causing the cutting knives or blades to sever the wire and causing the stripping knives to cut the insulation.
Wire gripping units, located upstream and downstream of the cutting and stripping station, grip the wire, and the cut length. The gripping units move the wire and the cut length in opposite directions so as to strip the insulation from the ends of the wire and from the cut length. As a result, guiding the axial movement of the wire through the cutting and stripping station and gathering the wire such that it may be located by the wire gripping unit downstream of the blades is of utmost importance.
Prior attempts to control the gathering and guiding of the wire through the cutting and stripping station have significant disadvantages. For example, in Gudnestad, U.S. Pat. No. 3,909,900, a reciprocating wire guide tube is disclosed. As the wire is axially moved through the cutting and stripping station, a guide tube is extended through therewith, and retracted in order to allow the closure of the blades. This system offers several disadvantages in that the extension and retraction of the wire guide tube increases the time required to process the wire. Further, the wire guide tube is sized for either the maximum cross section of the wire to be processed, in which case it is not at an optimum size for the smaller cross sectional wire, or the guide tube has to be changed which is costly and takes away from the process time. In addition, the wire guide tube does not allow for an enlargement on the lead end of the wire, such as a terminal or the like to pass therethrough.
In the alternative, wire guides such as those shown in Hoffa, U.S. Pat. No. 5,253,555 have been used. However, these types of wire guides have similar types of disadvantages. For example, the opening and closing of the guide members increases the cycle time for processing the wire. Further, the wire guide must be sized for the largest cross section of wire to be processed. As such, the use of different sized wire guides requires the additional costs associated with the manufacture of the wire guides and the downtime associated with changing of the wire guides for different sized wires. In addition, as with the wire guide tube disclosed in the '900 patent, the wire guide disclosed in the '555 patent does not allow terminals on the end of the wire to pass therethrough.
Blaha, U.S. Pat. No. 4,856,187 discloses an attempt to provide a wire gathering mechanism for gathering electrical wire or the like in a cutting and stripping station in order that the wire may be found by another handling device downstream of the knives. The wire gathering mechanism disclosed in the '187 patent has several disadvantages including the cost of the parts, and the difficulty in actuating the mechanism. Further, the wire gather mechanism disclosed in the '187 patent may add to the wire overhang which, in turn, reduces control of the wire during further processing.
Therefore, it is a primary object and feature of the present invention to provide a device for cutting and stripping insulated wire which allows for the gathering of wire of different gauges.
It is a further object and feature of the present invention to provide a device for cutting and stripping insulated wire having a gathering device which accommodates wire having terminals or the like mounted to the lead end thereof.
It is a further object and feature of the present invention to provide a device for cutting and stripping wire which may be programmed to adjust to cut and strip wire of various gauge sizes.
It is a still further object and feature of the present invention to provide a device for cutting and stripping insulated wire which simply and easily wipes the insulation slugs off the stripping blades after the stripping operation.
In accordance with the present invention, a device for gathering, cutting and stripping insulated wire is provided. The device includes first and second cutterhead assemblies. Each cutterhead assembly includes a central cutting knife and a pair of stripping blades spaced laterally on either side of the cutting knife. Upstream and downstream positioning head assemblies are also provided. The upstream positioning head assembly positions the insulated wire between the cutting knives of each cutterhead assembly for cutting and stripping.
A wire gathering element is mounted to each cutterhead assembly. Each wire gathering element has a planar portion for gathering the wire position therebetween by the upstream positioning head assembly.
In operation, after the insulated wire has been positioned between the cutterhead assemblies, the wire gathering elements, the cutting knives and the stripping blades are moved toward each other simultaneously such that the planar portions of the wire gathering elements gather the wire to align the wire with a gripping unit downstream of the cutting head assemblies.
At a predetermined position, the wire is gripped by the downstream gripping unit and an additional, gripping unit upstream of the cutterhead assemblies. Thereafter, with the gathering elements remaining in a fixed position, the cutting knives and the stripping blades are brought together to cause the cutting knives to sever the wire, and to cause the stripper knives to cut the insulation.
After the insulation is cut, the gripping units are separated away from each other so as to strip the slugs of insulation away from the ends of the wire. The cutting knives and the stripping blades are then retracted so as to pass through slits in the wire gathering elements. The wire gathering elements, in turn, wipe off any slugs of insulation which may have stuck to the stripping blades. The cutting knives, stripping blades, and wire gathering elements return to their original, home position in order to await the positioning of another portion of insulated wire between each cutterhead assembly.
The movement of the cutting knives, the stripping blades and the wire gathering elements are controlled by a central processing unit. The central processing unit actuates a servo motor which, in turn, controls movement of the elements.